Macro assert_let_timeout

macro_rules! assert_let_timeout {
    ($timeout:expr, $pat:pat = $future:expr) => { ... };
    ($pat:pat = $future:expr) => { ... };
}

Available on crate feature testing only.

Like assert_let, but with the possibility to add an optional timeout.

If not provided, a timeout value of 100 milliseconds is used.